Tamping device for concrete-block machines.



P. N. NELSON.

TAMPING DEVICE FOR CONCRETE BLOCK MACHINES.

APPLICATION FILED MAY 15. l9l6.

1,220,532. I PatentedMan-zv, 1917.

2 SHEETSSHEET I.

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TAMPING DEVICE FOR CONCRETE BLOCK MACHINES.

APPLICATION FILED MAY 15, I916.

Patented Mar. 27, 1917.

2 SHEETS-SHEET 2- f ATE FATENT @T FTQE,

PETER N. NELSON, OF MINNEAPOLIS, MINNESOTA.

TAMPING DEVICE FOR CONCRETE-BLOCK MACHINES.

To all whom it may concern:

Be it known that I, PETER N. NELSON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Tamping Devices for Concrete-Block Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide a simple and efficient tamping device for concrete block machines; and to such ends, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

The invention is illustrated in the accompanying drawings wherein like characters indicate like parts throughout the several views.

Referring to the drawings:

Figure 1 is a front elevation showing the improved tamping device and illustrating its relation to the block machine; and

Fig. 2 is a side elevation of the tamping device.

The numeral 1 indicates a rectangular framework which is rigidly secured to and depends fro-m suitable overhead supports, such as beams 2. The numeral 3 indicates a shaft journaled in suitable bearings 4 on the frame 1, and provided at one end with a pulley 5, and at its other end with a crank 6. The end of the crank 6 is preferably equipped with a roller 7. The tamping head 8 is rigidly secured to the lower ends of parallel vertical bars of a yoke-like plunger 9 that works vertically through guides 10 on the lower portion of the frame 1 and is also guided by grooved rollers 11 journaled to brackets 12 on the sides of said frame. At its upper portion, the plunger yoke 9 is provided with a horizontal bar portion 9 that extends preferably a little more than one-half way across the same. Above the bar 9, said plunger has an upward extension 9', for a purpose which will presently appear.

Under rotation of the crank shaft in the direction of the arrow marked on Fig. 1, the roller 7 of the crank 6, on its upward stroke will engage the bar 9 and raise the plunger 9 and tamping head 8 until the said crank passes its upper vertical position,

Specification of Letters Patent. lPgmtgnfgqgd Eial'. 2'? 191 1 Application filed May 15, 1916.

Serial No. 97,518.

whereupon, the roller 7 will run into the space afforded by the extension 9*, thereby permitting the plunger and tamping head to drop under the action of gravity. The tamping head is thus caused to strike the mixed sand and cement 3 and tap the same within the mold y of the block forming machine. This tamping head is made in one piece, or in other words, is a solid element or unit, but may, of course, have any suitable clearance passage in the cores of the mold, where such cores are employed, as in making hollow blocks. Obviously, under rotation of the crank shaft, the tamping head will intermittently raise and drop, depending on the speed of rotation of the said crank shaft, and it will always be lifted to a definite height, but can drop to variable distances to adapt itself to the sand in the mold.

-A novel device is provided for holding the tamping head in a raised inoperative position with the horizontal bar 9 of the plunger 9 just above the uppermost position of the crank roller 7, so that under rotation of the crank shaft, there will be no engagement between the crank and the plunger. To this end, the tamping head 8 is provided with an anchor strap 13 shown as projected upward from its intermediate portion. This strap 13 is provided with an eye or perforation for engagement with the hooked lower end 14.- of an anchoring bar 15. A pivot bolt 16 rigidly secured to the lower portion of the frame 1 is extended through a vertical slot 17 in the intermediate portion of the anchor bar 15, thus pivoting the said bar to the said frame 1 with freedom for pivotal and limited vertical sliding movements. An operating lever 18 is pivoted to the upper end of the anchoring bar 15 and to a fulcrum link 19, the lower end of which latter is pivoted to the frame 1 by a bolt 20. On the frame 1 is a lock lug or detent 21 upon which the lever 18 may be engaged and disengaged at will, by slight lateral movement. hen the lever 18 is engaged with the lug 21, the anchor bar 15 will be raised so that the lower extremity of the slot 17 thereof, is engaged with the pivot bolt 16, and in this position of the parts, the horizontal bar 9" of the plunger 9 will be held upward slightly beyond the reach of the crank roller 7 so that the said crank shaft may then run idle, noiseless, and without any action whatever, on the plunger. A stop 22 on the lower portion of the frame 1 limits the movement of the upper portion of the an chor bar 15 toward the left, and, consequently, the movement of the hook 1-1 toward the right, in respect to Fig. 1.

'VVhen it is desired to engage the hook 14 with the anchor strap 13, the lever 18 is dis engaged from the lug 21, and its outer end is forced upward, so as to move the anchor bar 15 downward, and at the same time, the said anchor bar is yieldingly forced against the stop 92, so that the beveled lower portion of the hook 1st will then be within the line of movement of the anchor strap 13. lVhen this is done, the forced upward movement of the plunger 9 and tamping head 8 will cause the anchor strap 13 to cam itself into engagement with the depressed hook 14:,

and in which way, the said hook will be automatically engaged with the said anchor strap and the tamping head and plunger will be caught and held against dropping movement. Then, by raising the anchor bar and engaging the lever 18 with the lug 21, the tamping head and plunger will be again anchored or hung up in their inoperative positions with clearance between the crank shaft and the said plunger.

As shown, the bolt 23 that pivotally connects the lever 18 to the bar 15, is connected to the bolt 16 by a coiled spring 24:, and to the bolt 20 by a coiled spring 25. lVhen the lever 18 is releasedfromthe lug 21, and from the hand of the operator, the two springs noted will pull the anchor-bar 15 downward and the spring 25 will hold the hook 14 toward the left and out of the path of movement of the anchor st 'ap 18, so that there will be no automatic engagement between the said strap and hook 1 1 until the lever 18 is pushed toward the left, so as to bring the hook 14: into the path of movement -of said strap, whereupon, the-automatic engagement above noted will, of coursetake place.

What I claim is:

1. A tamping device comprising a crank shaft, and a ver ically movable plunger equipped with a tamping head and provided with a horizontal upper portion with which the crank of said shaft engages under its upward movement, and from which it is released from its downward movement, an anchor strap attached to said tamping head, a

hook-equipped anchor bar pivotally supported above said tamping head and automatically engageable with said anchor strap in one position, and a lever connection for raising said anchor bar into a position in which it will hold the said tamping head with saidplunger upward beyond the heads of said crank.

2. A tampmg device comprising a yokelike'vertically movable plunger equipped at -upwardly extended crank clearing'opening,

and a rotary shaft having a crank engageable with said horizontal upper portion of,

said plunger underits upward movement, but disengageable therefrom in its clownward movement, an anchor strap attached to said tamping head, a hook-equipped anchor bar pivotally supported above said tamping head and automatically engageable with said anchor strapin one position, and a lever connection for raising said anchor bar into a position in which it will hold the said tamping head with said plunger upward be yond the heads of said crank. V

3. A tamping device comprising a' crank shaft, and a vertically 'movable plunger equipped with a tampinghead and provided with a horizontal upper portion with which the crank of said shaft engages under its upward movement, and from which it is released from its downward movement, an anchor strap attached to said tamping head, a hook-equipped anchor bar pivotally supported above said tamping head and automatically engageable with said anchor strap in one position, and a lever connection. for raising said anchor bar into a position in which it will hold the said tamping head with said plunger upward beyond the heads of said crank, and a stop with whiclrsaid lever is engageable tohold said anchor bar in its raised position.

4. A-tamping device comprising a crank shaft and I a vertically movable plunger equipped with a tanuping head and provided with a horizontal upper portioirwith which the crank of said shaft enga es under its upward movement, and from which it is released from its downward movement, an anchor strap attached to said tamping head, a hook-equipped anchor bar pivotally supported above'said tamping head and automaticallyengageable with said anchor strap in one position, a lever connection for raising said anchor bar into a position inwhich it will hold the said tamping head with said plunger upward beyond the heads of sa d crank, a stop with which said lever is engageable to hold said anchor bar in its raised position, and a spring connection for holding said anchor bar normally out of the path Copies of this patent may be obtained for five cents each, by eddressinglthe Commissioner of Patents.

Washington, D. 0. 

